Volume 67 - 2004 - Fasc.3 - Symposium
Non invasive markers of liver fibrosis in hepatitis C
Liver fibrosis reflects a loss of homeostasis between fibrogenesis and matrix degradation (1).
In the extracellular space, matrix degradation occurs as a consequence of the action of enzymes called matrix metalloproteinases (MMPs), themselves inhibited by tis- sue inhibitors (TIMP 1-4) which are protease inhibitors. Chronic liver injury, whatever the cause (alcohol, virus, non alcoholic liver disease, biliary disease,...), lead to hepatic stellate cells activation, producing a fibrogenic environment within the liver, leading to extensive fibro- sis and cirrhosis, through a combination of extracellular matrix (including collagens, non collagenous glycopro- teins and proteoglycans) overproduction, diminished MMP activation and inhibition of active MPPs by TIMPs.
Is histology useful for the assessment of the efficacy of immunosuppressive agents in IBD and if sO. how should it be applied ?
Crohn's disease and Ulcerative colitis are two chronic relapsing inflammatory bowel diseases of unknown etiology. Both conditions are characterized by a considerable morbidity and have an impact upon the social and economic aspects of the patients life. At pre- sent, medical treatment is mainly aiming at the control of the inflammation. Drugs used for ulcerative colitis can induce micro- scopic healing of the mucosa. Similar results have been obtained recently with immunomodulatory drugs in Crohn's disease. The cost of these drugs is however high and the use of these drugs can be associated with side effects. Furthermore, many of the drugs need to be given for a long period. Therefore it is appropriate to assess the efficacy of the drugs before commercial use and even when used in routine practice. For both ulcerative colitis and Crohn's disease, clinical parameters combined in indices and endoscopy are commonly used together with some laboratory tests for the assessment of disease activity. In ulcerative colitis, histology has been used along with the other instruments for the measure- ment of disease activity because it was shown that the mucosal lesions could improve. More recently, histology has also been used for Crohn's disease. Routinely, disease activity when assessed with microscopy, should be divided into mild, moderate and severe. For drug trials and study purposes, more objective scoring systems should be used. Preferentially, a generally accepted score is used. This allows comparisons between different studies. Different scor- ing systems have been designed for ulcerative colitis and Crohn's disease. For the latter, multiple biopsies should be analysed. Most scoring systems still need validation.(Acta gastroenterol. belg., 2004, 67, 285-289).
Endocrine tumours, somatostatin and somatostatin receptors
Somatostatin blocks the release of numerous growth factors and is therefore a potent inhibitor of cell division and/or secretion. It exerts its effects through binding to somatostatin receptors. Five different subtypes of such receptors are identified (ssTR1 to ssTR5), having various tissue expression. The detection of their presence in tumours can be performed on histological sections and has potential therapeutic implications. (Acta gastroenterol. belg., 2004, 67, 282-284).
Histological scoring of chronic hepatitis
Liver biopsy is considered to be the most specific analysis to assess the nature and severity of liver disease. In case of chronic hepatitis, scoring liver biopsies is an established part of the pathol- ogist's work. Four different scores are most often used : the Scheuer, Ludwig and French METAVIR systems, which are fairly simple, and the Ischak score, which is more complex. All systems generate scores, which are based upon inflammatory activity (the grade) and fibrosis (the stage), with splitting of these two compo- nents. To be valid in routine analyses, a scoring system must be clinically relevant, reproducible and simple to understand and to apply. Scoring will then be helpful to study series of patients and to evaluate the efficacy of new therapeutic strategies. However, a score does not replace the study of a liver biopsy and the generat- ed numbers does not correspond to true measurements. Furthermore, its accuracy will always depend on adequate sam- pling. (Acta gastroenterol. belg., 2004, 67, 290-293).
Endometriosis is not only a gynecologic disease
The efficacy of medical and surgical treatment of endometriosis and pelvic pain is a source of questions and controversies.
Complete resolution of endometriosis is not yet possible but therapy has essentially three main objectives : 1) to reduce pain ; 2) to increase the possibility of pregnancy ; 3) to delay recurrence for as long as possible.
In case of moderate and severe endometriosis, operative laparoscopy must be considered as first line treatment. The mean pregnancy rate of 50% reported in the literature following surgery provides scientific proof that operative treatment should first be undertaken to give our patients the best chance of conceiving naturally.
In case of rectovaginal adenomyotic nodules, surgery must also be considered as first line therapy, medical therapy being relative- ly inefficacious.
Careful preoperative examination is mandatory (transrectal sonography, magnetic resonance imaging, bowel barium enema or intravenous pyelography) to evaluate potentially severe com- plications of the disease. (Acta gastroenterol. belg., 2004, 67, 272- 277).
Medical Treatment of Chronic Anal Fissure. Where do we stand on Reversible Chemical Sphincterotomy ?
Anal fissure is a common problem which can evolve to chronici- ty. Chronic anal fissure is thought to be an ischemic ulceration related to sphincter hypertonia. Lateral internal sphincterotomy, the most common treatment for chronic anal fissure, may cause permanent injury to anal sphincter leading to fecal incontinence. To avoid such side effect were developed medications producing a temporary or reversible sphincterotomy reducing the sphincter pressure only until the fissure has healed : nitrates, calcium chan- nel antagonists and botulinum toxin. Authors aimed to summary the state of research on such treatments (efficacy, side effects, recurrence risk) and to clarify the role of these different medical options in the current treatment of chronic anal fissure. (Acta gastroenterol. belg., 2004, 67, 265-271).
Endoscopic ultrasound guided fine needle aspiration in biliary and pancreatic diseases : pitfalls and performances
Endoscopic ultrasound guided fine needle aspiration (EUS- FNA) has become the most accurate modality for characterization of pancreatic cystic and solid lesions, for differential diagnosis of indeterminate pancreatic masses and for locoregional staging of pancreatic and extrahepatic biliary tumours. EUS-FNA should also be performed in distant lymph nodes, ascites, liver, adrenal and mediastinal metastatic locations. Experienced groups reach a sensitivity over 85% with a 90-100% specificity, a positive predic- tive value of 98-100%, a negative predictive value of 44-80%, and an accuracy of 75-84% in evaluation of pancreatic masses. Morbidity rate (acute pancreatitis, infection, haemorrhage, perfo- ration) is very low being around 1-2% and risk of peritoneal seed- ing was shown to be significantly lower than percutaneous CT guided FNA. The performance of this technique is dependent on the endoscopist and cytopathologist experience, the location, size and consistency of the tumour and the number of passes in the lesion. The type of echoendoscope or needle used does not influ- ence the results, whereas it remains debated if presence of the cytopathologist on site might improve FNA performances. These last years, a new liquid-based cytology technique has been devel- oped to process the specimen. Different methods exist to prepare this type of material and all these techniques improve EUS-FNA performance by decreasing the number of inadequate specimens and by increasing the possibility to obtain cell blocks allowing for ancillary techniques such as immunohistochemistry and mole- cular biology. (Acta gastroenterol. belg., 2004, 67, 294-300).
